1. Field of Invention
This invention is a multi-functional tool to assist truck drivers with the operation of releasing the fifth wheel lock on trucks and tandem locking pins on trailers equipped with movable axles.
2. Background of Invention
The invention described in the following patent application is for use on semi truck and trailer type equipment. The sliding of the trailer tandems adjusts the load balance and it also allows the driver to change the king pin to center of axle length to meet different State's bridge formula and or length laws. Currently to manually pull these release handles one must bend at the waist and reach under the trailer. The possibility of back injury increases when pulling release handles which are positioned under the edge of most trailers. Our device is a multi-functional tool, which can be used as an extension handle for manual pulling of fifth wheel, and tandem release handles without having to bend at the waist. Our invention incorporates a hook on one end with a handgrip handle on the opposing end allowing the driver to manually hook and pull the trailer release handle on a fifth wheel or the release handle on a sliding tandem without bending at the waist. If the tandem slide lock pins on the trailer tandem are lined up with the fixed holes on the trailer body, releasing the locking pins is easily performed manually. The danger of injury occurs if the locking pins on the trailer tandem frame are not aligned with the holes on the fixed track binding the pins in the locked position. When this condition occurs many drivers over strain their back and or shoulders attempting to manually release the sliding tandem locking pins. The described invention incorporates a screw jack and a spring member to preload the locking pins with spring tension when they are bound in the locked position without physical strain. The driver then applies the trailer brakes and uses the power of the truck to rock the trailer back and forth until the pins are aligned allowing the tension of the spring to pull or lift the tandem release handle, releasing the sliding tandem locking pins. Some devices use leverage to apply brute force to the release handle increasing the possibility of damage to the tandem slide lock mechanism and or injury to the driver. With normal wear or overstressing of components the locking mechanism released detent on the release handle may not fully release the locking pins. If the locking pins are not fully retracted they can rub the track between the holes and vibrate the handle off the detent and allow the pins to return to the locked position. Drivers are forced to use many makeshift methods to place the locking pins in a fully released position. Our invention does not rely on the detent on the release rod to hold the locking pins in the fully released position. Our invention extracts and holds the release rod at its maximum travel every time. Attachment of our device, to the tandem frame, uses the manual pull hook on the end of the device. This innovation makes it simple, secure and requires no modification to most trailers. In addition to reducing complexity it also allows the device to conform to the release rod angle, which changes as the rod extract the locking pins. By attaching the device to the sliding tandem frame it holds the locking pins released until the operator is satisfied with the position of the trailer body. The drive then removes the tension on the spring and pins return to the locked position. Another unique feature of our device is the use of a lanyard, also called choker loop, to attach the spring member to the release rod, instead of a metal hook as most other devices use. This attachment also eliminates the need to use the handle as an attachment point. Brute force tools that create excessive force on the handle commonly bend release handles. Other features include attached storage hooks for the spring member, and a crank handle that attaches using a standard ⅜ inch square socket, allowing it to be removed and a battery or air powered drill or impact tool to turn the jack screw. Using a battery or air-powered tool increases the speed and ease of tensioning the spring member, reducing the time required to adjust the sliding tandems. Additionally our device folds for compact storage and as an added utility in the folded position, the extension arm doubles as an attachment socket for lift type tandem release levers.